Method and apparatus for producing corrugated paperboard



J. P. GEBBIE 2,987,105 METHOD AND APPARATUS FOR PRODUCING CORRUGATEDPAPERBOARD June 6, 1961 Filed Dec. 24, 1957 INV ENTOR.

A TTOPNEK.

2,987,105 METHOD AND APPARATUS FOR PRODUCING CORRUGATED PAPERBOARD JamesP. Gebbie, Trenton, NJ., assignor, by mesne assignments, to KoppersCompany, Inc., Pittsburgh, Pa., a corporation of Delaware Filed Dec. 24,1957, Ser. No. 704,946 8 Claims. (Cl. 154-32) In ythe production ofcorrugated paperboard it has long been conventional to pass theconstituent materials through a so-called doublebacker machine whereinsingle faced cornlgated paper carrying freshly applied adhesive on theexposed peaks of its corrugations, is bonded to a facing sheet, thesuperposed sheets being subjected to heat and pressure in thedoublebacker to set the adhesive and dry out moisture, producing atraveling sheet of corrugated paperboard wbich then passes through aslitting and scoring mechanism by which the board is dividedlongitudinally into sections of desired widths, after which the sectionspass through a cutoff mechanism which severs them transversely intoblanks of desired sizes.

In operation-for example when the slitter-scorer and the cutoff arebeing reset to produce blanks of ditferent sizes, it is sometimesdesired either to stop the feed of the material through the doublebackerfor a short period, or to temporarily operate the latter at speedmarkedly lower than normal. When thus slowed down or held stationary,the material in the heating section of the doublebacker is subjected tothe heat thereof for an abnormally long period.

The present invention aims to alleviate injury to the corrugatedpaperboard as caused by such abnormally long heating. In accordance withthe invention, under the above abnormal operating conditions moisture isadded to the material while passing to the heating section of thedoublebacker `or while passing therethrough, or both, by subjecting thetraveling material to moisture laden sprays or equivalent wettingapparatus which is inactive in the normal range of production speeds,but is automatically cut into action when the speed of travel becomesabnormally low, and remains in action so long as the material keeps ontraveling abnormally slowly through the doublebacker, beingautomatically cut out of action when the doublebacker stops, and alsowhen normal production speed is resumed. The `additional moisturecontent thus supplied to the partially completed paperboard enables thelatter to remain in the heating section of the doublebacker withoutinjurious overheating or drying, for the short shutdown or slowdownperiods needed for resetting the machinery as aforesaid to produceblanks of different sizes. Further objects and advantages of theinvention will be in part obvious and in part specifically referred toin the description hereinafter contained which taken in conjunction withthe accompanying drawings discloses somewhat schematically, a preferredform of doublebacker arranged to operate in accordance with theinvention; the disclosure however should be considered `as merelyillustrative of the invention in its broader aspects.

In the drawings:

FIG. 1 is a longitudinal sectional view, largely schematic, takenthrough a doublebacking machine equipped to function in accordance withthe invention;

FIG. 2 is a section on line 2-2 of FIG.1 looking in the direction of thearrows;

FIG. 3 is a diagram showing schematically, electrical circuitsappropriate for controlling spray apparatus of the character shown inFIGS. 1 and 2.

The invention is shown in FIG. 1 as applied to a doublebacking machinehaving at its entrance end, a guide pulley 1 for the upper conveyor belt2 which runs throughout the full length of themachine, a drive pulley 3for such belt Patented June c, 1961 fice being provided at the deliveryend of the machine. As indicated at the right of FIG. l a single facedcorrugated paper web 4 is fed into the entrance end of the machine, theexposed peaks of the corrugations being coated with adhesive as is usualin the art, and at the entrance end of the machine, the web 4 is broughtinto contact with a traveling facing sheet 5 which runs over a guideroll 6 and an apron 7 located at the entrance end of the machine. In theinitial section of the machine the corrugated paperboard thus formed isfed progressively by the belt 2 over a series of heating plates 8 whichaid in setting the adhesive and drying out the material, the plates 8,apron 7 and roll 6 being usually steam heated. After passing the heatingplates above mentioned, the paperboard passes in between the abovedescribed upper conveyor belt 2, and a lower conveyor belt 9 which isshown -at the left of FIG. l `as passing yaround a drive pulley 10, sothat a continuous length of corrugated paperboard passes out at thedelivery end of the machine. The machine as thus far described may beunderstood as of known or any appropriate form.

In the normal range of production speeds, the heat to which the materialis subjected in passing through the machine, is sufficient to set theadhesive and dry out the board without injury to the latter due tooverheating, and in accordance with the present invention, underconditions where the feed of the material through the machine istemporarily slowed down or stopped, the moisture content of the materialbeing thus subjected to the heat of plates 8 for `an abnormally longperiod, is increased sufficiently to avoid overheating of the materialunder the above conditions.

As shown in FiG. 1, a spray apparatus may be employed, which has aheader 11 extending transversely across the machine adjacent lthe pathof travel of the material and located at ya point Where the moisturecontent thereof is to be increased, the header 11 being provided with aseries of perforated nozzles 12 which distribute the moisture in theform of tine sprays over the surface of the material yas it travels pastthe header 11. The header 11 may be supplied with hot water by a pipe 13which extends through one of the side frames 14 of the machine.

The header 11 shown in FIG. 2 may be understood as interposed betweenthe rst and second steam plates 8 which appear at the entrance end ofthe machine as shown in FIG. l, `and similar headers as shown at 11ALand 11B in FIG. 2, may be provided at points spaced along the heatingsection of the machine. Also a similar header 11C may be provided`adjacent the apron 7, to meisten the under surface of the facing sheet5 als it enters the machine, which surface will be directly exposed tothe heater plates S while the material is in the machine. A similarheader 11D is also shown at the right of FIG. l, in position to applymoisture to the upper exposed surface of the single faced paper web 4 asthe latter passes into the machine.

As shown at the left of FIG. 2, water for the above purposes may besupplied through a pipe 15 into which steam is injected from a pipe 16to heat the water, a pipe 17 running along the machine being provided tofeed the various pipes 13 above mentioned. As later described in greaterdetail, the ow of water for the above purposes may be turned on and offby a valve 18.

FIG. 3 shows schematically an electrically controlled system forcontrolling the moisture supplied to the paperboard `for the abovepurposes. In FIG. 3 a direct current motor 19 is shown and should beunderstood as driving the conveyor belts 2 and 9 above mentioned,circuit to the motor 19 being opened and closed by a switch 20 to startand stop the feed of material through the machine, appropriateadjustment being provided to afford intermediate speeds of feed as iscustomary in the art. The motor 19 may be powered from any suitablesource, as

for example the generator of a motor-generator set. FIG. 3 also shows aservice circuit comprising the conductors 21, 22 and relays 23, 24 whichcontrol circuit to a coil 25 which should be understood as controllingthe valve 18 previously mentioned. A brake 26 is also indicatedschematically in FIG. 3, and should be understood as activated whenswitch 20 is opened, to bring the conveyor belts '2 and 9 quickly torest.

The relay 23 should be understood as being of the so-called voltageoperated type, and adjusted to hold the circuit 21, 22 closed so long asthe speed of feed as controlled by motor I9, exceeds for example 100 ft.per min. The relay 24 should be understood as set to open at Zerovoltage, i.e. when motor 19 is at rest so that the material liesstationary in the machine. So llong as both of the relays 23 and 24 areclosed as will be the case in the normal range of operating speeds offeed, circuit to the coil will be closed and the latter will hold thevalve 1S closed. Thus under normal production speeds of feed noadditional moisture will be supplied to the material passing through themachine, but when the rate of feed drops down below 100 ft. per min.,relay 23 will open to deenergize the coil 25 and thereby open the valve18 to supply extra moisture to the material passing through the heatingsection of the machine which includes the steam plates 8. So long as themachine continues running at abnormally low speed the supply ofadditional moisture will continue, but if the machine is stopped, relay24 will open to complete circuit to the coil 25 through the conductors27, 2S and 29, thereby closing valve 18 to cut off the moisture sprays,and at the same time energizing the brake mechanism 26 to stop the feedof material through the machine.

When switch 20 is closed to start up the machine, relay 24 will closebut so long as the relay 23 remains open, all circuits leading throughthe coil 25 Will be open and therefore the valve 18 will be open. Inother Words while the machine is starting up and until a rate of feed ofsay 100 ft. per min. is reached, the moisture spray apparatus will be inaction to protect the material against over-heating while travellingslowly past the steam plates 8. When the feed attains a higher speedrelay 23 will close, thereby closing circuit to the coil 25 through bothrelays to cut oif the moisture sprays so that the latter remain inactivewhen the rate of yfeed is within the normal production range.

In the normal course of production, the machine is stopped or run atabnormally low speed only occasional-ly for short periods measured inseconds, as needed while the mechanisms to which the continuous lengthof paperboard passes after leaving the doublebacker, are beingreadjusted to produce blanks of different dimensions. Such mechanismshave long been provided with devices for resetting them to differentdimensions, which devices come into action upon the completion of a runof blanks of some other size. Such adjustments may be quickly made andtherefore length of material to which extra moisture need be suplied toavoid overheating, is short. In other words the extra moisture added tothe material in accordance with the present invention, need only be thatwhich will protect against overheating the length of material which liesstationary in the heating section of the ma-V chine or passes veryslowly therethrough, for a period of time measured in seconds. The extramoisture thus added to the material during the above mentioned shortperiods, is kept below an amount which would result in the production ofincompletely dried out corrugated paperboard. The spray apparatus 11B ispreferably so positioned that the portion of the paperboard moistenedthereby will approximately reach the end of the heating zone constitutedby the steam plates 8, by the time when brake 26 halts the travel of thepaperboard, to the end that the portion of the paperboard which liesstationary in the heating zone shall be adequately moistened, withoutexcessively moistening the portion of the paperboard which 4 e haspassed beyond the heating zone before the machine stops.

I claim:

l. A double backing machine of the character described, having a webheating section, means for guiding a single faced corrugated paper webto pass to said heating section, means for applying adhesive to theexposed peaks of the corrugations of such web when travelling towardsaid heating section, means for guiding a facing sheet into contact withsaid peaks when travelling to said heating section to form partiallycompleted corrugated paperboard, means adjustable as to operating speedfor feeding said partially completed paperboard through said heatingsection, apparatus for increasing the moisture content of said partiallycompleted paperboard, and means responsive to changes in speed of saidfeeding means for cutting said apparatus into action when said feedingmeans is operating at low speed and cutting said apparatus out of actionwhen said lfeeding means is adjusted to operate at higher speed.

2. A double backing machine of the character described, having a webheating section, means for guiding a single faced corrugated paper webto pass to said heating section, means for applying adhesive to theexposed peaks of the currugations of such web when travelling towardsaid heating section, means for guiding a facing sheet into contact withsaid peaks when travelling to said heating section to form partiallycompleted corrugated paperboard, means adjustable as to operating speedfor feeding said partially completed paperboard through said heatingsection, apparatus for increasing the moisture content of said partiallycompleted paperboard, and means responsive to changes in speed of said`feeding means for cutting said apparatus into action when said feedingmeans is operating at Llow speed and cutting said apparatus out ofaction when said feeding means is stopped.

3. A double backing machine of the character described, having a webheating section, means for guiding a single faced corrugated paper webto pass to said heating section, means for lapplying adhesive to theexposed peaks of the corrugations of such web when travelling towardsaid heating section, means for guiding a facing sheet-into contact withsaid peaks when travelling to said heating section to form partiallycompleted corrugated paperboard, means adjustable as to operating speedfor feeding said partially completed paperboard through said heatingsection, apparatus for increasing lthe moisture content of saidpartially completed paperboard, and means responsive to changes in speedof said feeding means for rendering said apparatus inactive in thenormal range of production speeds of feed, but cutting said apparatusinto action when said feeding means is operating at speeds less thansaid normal range, and cutting said apparatus out of action when saidfeeding means is stopped.

4. A double backing machine of the character described, having a webheating section, means for guiding a single lfaced corrugated paper webto pass to said heating section, means for applying adhesive to theexposed peaks of the corrugations of such web when travelling towardsaid heating section, means for guiding a facing sheet into contact withsaid peaks when travelling to said heating section to form partiallycompleted corrugated paperboard, means adjustable as to operating speedfor feeding said partially completed paperboard through said heatingsection, yapparatus for increasing the moisture content of saidpartially completed paperboard, and means responsive to changes in speedof said feeding means for cutting said apparatus into action when saidfeeding means is operating at low speed and cutting said apparatus outof action when said feeding means is adjusted to operate at higherspeed, said moisture increasing apparatus having a spray pipe disposedtransversely of the path of travel of said facing sheet, in position todirect moisture onto the surface of said sheet.

5, A double backing machine of the character described, having a webheating section, means for guiding a single `faced corrugated paper webto pass to said heating section, means for applying adhesive to theexposed peaks of the corrugations of such web when travelling towardsaid heating section, means for guiding a facing sheet into contact withsaid peaks when travelling to said heating section to form partiallycompleted corrugated paperboard, means adjustable as to operating speedfor feeding said partially completed paperboard through said heatingsection, apparatus for increasing the moisture content of said partiallycompleted paperboard, and means responsive to changes in speed of saidlfeeding means for cutting said apparatus into action when said feedingmeans is operating at low speed and cutting said apparatus out of actionwhen said feeding means is adjusted to operate at higher speed, saidmoisture increasing apparatus having a spray pipe disposed transverselyof the path of travel of said partially completed paperboard Whilepassing through said heating section, in position to direct moistureonto the surface of said partially completed paperboard while so passingthrough said heating section.

6. The method of producing corrugated paperboard which includes feedinga single faced corrugated paper web into a doublebacker, applyingadhesive to the exposed peaks of the corrugations of such web whiletraveling toward the doublebacker, feeding a facing sheet into thedoublebacker in contact with said peaks to form partially completedcorrugated paperboard, applying heat to said partially completedpaperboard While passing through said doublebacker, altering the speedof travel of said partially completed paperboard through thedoublebacker between zero and production speed, and subjecting at leastone of the constituents of said partially completed corrugatedpaperboard to a moisture-laden medium to increase the moisture contentof the portion of the partially completed corrugated paperboard which isbeing subjected to heat as aforesaid, when the speed of feed of saidpartially completed board through the doublebacker is lower than anormal production rate, and cutting said moisture-laden medium out ofaction when normal production speed is resumed.

7. The method of producing corrugated paperboard which includes feedinga single faced corrugated paper web into a doublebacker, applyingadhesive to the exposed peaks of the corrugations of such web whiletraveling toward the doublebacker, feeding a facing sheet into thedoublebacker in contact with said peaks to form partially completedcorrugated paperboard, applying heat to said partially completedpaperboard while passing through said doublebacker, altering the speed`of travel of said partially completed paperboard through thedoublebacker between zero and production speed, and subjecting at leastone of the constituents of said partially completed corrugatedpaperboard to a moisture-laden medium to increase the moisture contentof the portion of the partially completed corrugated paperboard which isbeing subjected to heat as aforesaid, when the speed of feed of saidpartially completed board through the doublebacker is lower than anormal production rate, and cutting said moisture-laden medium out ofaction when the speed of feed is reduced to zero.

8. A double backing machine of the character described, having a webheating section, means for guiding a single faced corrugated paper webto pass to said heating section, means for applying adhesive to theexposed peaks of the corrugations of such web when travelling towardsaid heating section, means for guiding a facing sheet into contact withsaid peaks when travelling to said heating section to form partiallycompleted corrugated paperboard, means adjustable as to operating speedfor feeding said partially completed paperboard through said heatingsection, apparatus for increasing the moisture content of said partiallycompleted paperboard, and means responsive to changes in speed of saidfeeding means for adjusting said apparatus to increase the moisturecontent of the partially completed paperboard when said feeding means isoperating at low speed.

References Cited in the le of this patent UNITED STATES PATENTS1,115,265 Weis Oct. 27, 1914 1,142,409 Ferres .Tune 8, 1915 1,179,941Langston Apr. 18, 1916 1,327,158 Hawkins Ian. 6, 1920 1,822,005Broughton Sept. 8, 1931 1,924,100 Barker Aug. 29, 1933 2,231,457 StephenFeb. 11, 1941 2,236,056 Grimm Mar. 25, 1941 2,288,129 Feldhausen et a1.June 30, 1942 2,309,728 Goettsch Feb. 2, 1943 2,365,352 Mott Dec. 19,1944 2,414,891 Oen Feb. 19, 1944 2,587,273 Aquilla Feb. 26, 19522,800,725 Holes --.w July 30, 1957

